The europium p-chlorobenzoate complex with 1, 10-phenanthroline was synthesizd in the ethanol solution. The crystal structure of the complex, Eu (p-ClBA)3·phen (p-ClBA: p-chlorobenzoate, phen:1,10-phenanthroline)...The europium p-chlorobenzoate complex with 1, 10-phenanthroline was synthesizd in the ethanol solution. The crystal structure of the complex, Eu (p-ClBA)3·phen (p-ClBA: p-chlorobenzoate, phen:1,10-phenanthroline), was determined by the X-ray diffraction. The complex crystalizes in triclinic,space group Pl with a=1. 0054 (2), b=1.1858(3), c=1.4349 (7) nm,α=110. 52(3), β=96. 52(3), γ= 101. 95(2)°, V=1. 5348(8) nm3, z=1, Dx=1. 729 g/cm3,Mr=1597. 72, T= 299±1 K. The coordination number of the europium ion is eight. The coordination geometry of the Eu3+ ion is a distorted square antiprism. In the 7F→5Do excitation spectrum of the complex, there is one sharp peak at 580. 04 nm. This shows that the complex has one Eu3+ site only. 5Do→7Fj(j=1 ̄4) luminescence spectra have been obtained by the selectively excited 5Do level of the complex, which indicates that Eu3+ ions in the complex have equally chemical environments. Raman spectrum shows more than one coordination modes for the carboxylate groups in the complex. This is in agreement with the results of the structure determination.展开更多
The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crysta...The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crystals at 457 and 657 nm, corresponding to the (D5/2-->I11/2)-D-4-I-4 and (2)G(7/2)-->I-4(9/2) transitions, respectively, excited by 808 nm of a laser diode, was observed at room temperature. The fluorescence intensity and the excitation light power have a linear relationship at 457 nm and a quadratic relationship at 657 nm.展开更多
The crystal structure of europium tri(dibenzoylmethanate) complex with 2.2'-bipyridyl,C70 H57 N2 O8 Eu, has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1. The cell ...The crystal structure of europium tri(dibenzoylmethanate) complex with 2.2'-bipyridyl,C70 H57 N2 O8 Eu, has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1. The cell dimensions are a=1.3375(1) nm.b=1.8591(2) nm, c=1.1339(3) nm,α= 95.89(9) °,β=93.36(1)°,γ=85.48(1)° and Z=2. The total number of 5413 independent reflections with I>3σ(I) were used for the structure determination. The final calculated R value is 0.039. The central europium ion is octa-coordinated by six oxygen atoms and two nitrogen atoms forming a distorted square antipnsm (SAP) with the local symmetry C1. Using the Eu3+ ion as a luminescence probe. the high resolution excitation and emission spectra measured at 77 K indicate only one Eu3+ site existing in the complex. The emission spectra of 5D0→7Fj transition display the symmetry of the Eu3+ site is C1.展开更多
The ionoluminescence (IL) spectra of a ZnO single crystal irradiated with 2.5?MeV H++ ions reveal that its intensity decreases with increasing the ion fluence, which indicates that the concentration of luminescen...The ionoluminescence (IL) spectra of a ZnO single crystal irradiated with 2.5?MeV H++ ions reveal that its intensity decreases with increasing the ion fluence, which indicates that the concentration of luminescence centers decreases with irradiation. The Gaussian decomposition results of the ZnO IL spectrum with a fluence of 1.77×10^11ions/cm^2 show that the spectrum is a superposition of energy levels centered at 1.75eV, 2.10eV, 3.12eV and 3.20eV. The four peaks are associated with electronic transitions from CB to VZnZn, CB to Oii, Znii to VB and the decay of self-trapped excitons, respectively. The results of single-exponential fitting demonstrate that different luminescent centers have different radiation resistance, which may explain why the emission decreases more slowly in the NBE band than in the DBE band. The agglomeration of larger point clusters accounts for the decrease in the concentration of luminescence centers and the increase in the concentration of non-luminescence centers, which indicates that the defect clusters induced by ion implantation act as nonradiative recombination centers and suppress light emission. The results of the photoluminescence spectra of a virgin ZnO single crystal and a ZnO single crystal irradiated with a fluence of 3.4××10^14ions/cm^2 show that compared with the virgin ZnO, the emission intensity of irradiated ZnO decreases by nearly two orders of magnitude, which demonstrates that the irradiation effect reduces radiative recombination and enhances nonradiative recombination. The conclusions of photoluminescence are consistent with the IL results.展开更多
A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been s...A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.展开更多
Er^3+ :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er^3 + ions in th...Er^3+ :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er^3 + ions in the crystal was measured by the ICP method. The absorption and emission spectra were also measured. On the basis of the spectra, the absorption cross-sections, emission spectrum FWHM and fluorescence lifetime of the crystal were calculated. From the properties mentioned above.展开更多
The effect of laser energy density on the crystallization of hydrogenated intrinsic amorphous silicon (a-Si:H) thin films was studied both theoretically and experimentally. The thin films were irritated by a freque...The effect of laser energy density on the crystallization of hydrogenated intrinsic amorphous silicon (a-Si:H) thin films was studied both theoretically and experimentally. The thin films were irritated by a frequency-doubled (λ= 532 nm) Nd:YAG pulsed nanosecond laser. An effective density functional theory model was built to reveal the variation of bandgap energy influenced by thermal stress after laser irradiation. Experimental results establish correlation between the thermal stress and the shift of transverse optical peak in Raman spectroscopy and suggest that the relatively greater shift of the transverse optical (TO) peak can produce higher stress. The highest crystalline fraction (84.5%) is obtained in the optimized laser energy density (1000 mJ/cm2) with a considerable stress release. The absorption edge energy measured by the UV- visible spectra is in fairly good agreement with the bandgap energy in the density functional theory (DFT) simulation.展开更多
The crystallographic properties and R aman spectra of the title compound ZnCd(SCN) 4, which is a new nonlinear optica l crystal(NLO), are reported for the first time. This crystal is orthorhombic and its space group i...The crystallographic properties and R aman spectra of the title compound ZnCd(SCN) 4, which is a new nonlinear optica l crystal(NLO), are reported for the first time. This crystal is orthorhombic and its space group is I - 4 with unit cell parameters a =1.113 5(0.2) nm, c =0.437 60(1) nm. There are two formulas per unit cell. Raman spectra of zinc cadmium thiocyanatec (ZCTC) are given and the electron activities in the crystal are shown.展开更多
The structure of Tb∶Mo∶PbWO4 crystals was investigated by Raman spectra and the results showed that the spectra were varied differently by doping dopants in different ranges of shift. Rotation-vibration, curving-vib...The structure of Tb∶Mo∶PbWO4 crystals was investigated by Raman spectra and the results showed that the spectra were varied differently by doping dopants in different ranges of shift. Rotation-vibration, curving-vibration and non-symmetrical stretching-vibration had been investigated on the spectra. Rotation-vibration intensity of [WO4]2-group is weakened and curving-vibration intensity is undergirded; low Mo6+ doping enhances the intensity of non-symmetrical stretching-vibration, with the concentration of Mo6+ increasing, the intensity is weakened. So it could be inferred that Tb3+ ion replaced the vacancy of Pb, when achieving at a certain concentration, Tb3+ ion would substitute for the lattice of Pb2+, Mo6+ ion would substitute for W lattice and generate [MoO4]2-new group, these are the main reason for the properties changing. Furthermore it could suggest that the impurity ions doped in tetrahedral positions, strongly affect the electron-phonon coupling in [WO4]2-, which makes the intensities of the vibration changed regularly.展开更多
Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has bee...Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C7H5N2NaO52.5H2O crystallizes in the monoclinic space group C2/c, with a(?) 16.408(3);b(?) 12.446(3);c(?) 13.716(3);(o) 126.34(3). The planar organic anion exists in a triketo-dihydroxyimino form with the C–O and C–N distances from 1.220(2) to 1.271(2)?? and from 1.292(2) to 1.293?? respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm-1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.展开更多
The crystal structure of spiro[2.2”]acenaphthene-1”-onespiro[3.3’]-5’-(2,3-dichlorophenylmethylidene)-1’-methylpipe-ridin-4’-one-4-(2,3-dichorophenyl) octahydroindolizine was elucidated by single crystal X ray d...The crystal structure of spiro[2.2”]acenaphthene-1”-onespiro[3.3’]-5’-(2,3-dichlorophenylmethylidene)-1’-methylpipe-ridin-4’-one-4-(2,3-dichorophenyl) octahydroindolizine was elucidated by single crystal X ray diffraction. The title compound C37H30Cl4N2O2, crystallizes in the orthorhombic system, space group P212121 with a = 8.4610(4) , b = 16.0926(6) , c= 23.8997(11) and Z = 4. The central piperidine ring adopts twisted conformation, the piperidine of octahydroindolizine ring is in chair conformation and the pyrrole ring is in slightly twisted envelope conformation. Details of the synthesis, NMR, crystal structure determination and intra- and inter- molecular interactions of the compound are given.展开更多
Reinvestigation of the growth of L-proline succinate (1) (Paramasivam and Ramachandra Raja, Journal of Crystallization Process and Technology, 2 (2012) 21 - 24;Balamurugaraj et al., Journal of Material Physics and Che...Reinvestigation of the growth of L-proline succinate (1) (Paramasivam and Ramachandra Raja, Journal of Crystallization Process and Technology, 2 (2012) 21 - 24;Balamurugaraj et al., Journal of Material Physics and Chemistry 1 (2013) 4 - 8) and L-threonine zinc acetate (2) (Puhal Raj and Ramachandra Raja, Photonics and Optoelectronics, 2 (2013) 56 - 64) is reported. Slow evaporation of an aqueous solution containing equimolar quantities of L-proline and succinic acid (for 1) and L-threonine and zinc acetate (for 2) results in the fractional crystallization of succinic acid (in the first case) and L-threonine (in the second case) and not any novel organic non-linear optical (NLO) crystals. In this paper, the usefulness of infrared spectra for correct product characterization is demonstrated.展开更多
According to the Van Uitert experimental equation, crystal-lattice environment of Eu^(2+) in the Sr_4Si_3O_8Cl_4 crystal was discussed. By adding Mg^(2+) to the host lattice, Sr_(4- x )Mg_ x Si_3O_8Cl_4∶Eu^(2+) was s...According to the Van Uitert experimental equation, crystal-lattice environment of Eu^(2+) in the Sr_4Si_3O_8Cl_4 crystal was discussed. By adding Mg^(2+) to the host lattice, Sr_(4- x )Mg_ x Si_3O_8Cl_4∶Eu^(2+) was synthesized and the emission peak shifted from blue-green (488 nm) to blue-violet (411 nm) with the increase of amount of the magnesium which replaced the strontium. By analyzing the spectra of Sr_(4- x )Mg_ x Si_3O_8Cl_4∶Eu^(2+) the two Eu^(2+) emission centers were found because of the change of crystal-lattice environment in the host and the crystal structure was obtained by X-ray diffraction data.展开更多
A new uranium(Ⅵ)-polycarboxylate framework with honeycomb(6,3) nets {[Zn(phen)_2(H_2O)_2][(UO_2)_2(BDC)_3]·2H_2O}n(1, BDC = benzene-1,4-dicarboxylate) was hydrotherrmally synthesized by the reactio...A new uranium(Ⅵ)-polycarboxylate framework with honeycomb(6,3) nets {[Zn(phen)_2(H_2O)_2][(UO_2)_2(BDC)_3]·2H_2O}n(1, BDC = benzene-1,4-dicarboxylate) was hydrotherrmally synthesized by the reactions of Zn(NO_3)_2·6H_2O with phenanthroine, UO_2(NO_3)_2·6H_2O and benzene-1,4-dicarboxylate. The complex was structurally characterized by FT-IR spectroscopy, powder XRD and X-ray single-crystal diffraction. Crystal data for 1: monoclinic, space group Cc with M_r = 1522.19, a = 14.9385(10), b = 20.4922(13), c = 15.9728(10) ?, β = 100.1240(10)°, V = 4813.5(5) ?~3, Z = 4, D_c = 2.100 g?cm^(–3), μ = 7.293 mm^(–1), F(000) = 2872, the final R = 0.0224 and w R= 0.0677 for 6522 observed reflections with I 〉 2σ(I). Hydrogen bonds and π-π stacking interactions contribute to the structural extension and stabilization. Experimental band gap of about 3.57 e V indicates its broad gap semiconductor nature. UV-Vis spectra and solid-state luminescence were discussed in detail. The compound exhibits photocatalytic activities for the degradation of rhodamine B.展开更多
YbAl3(BO3)4 crystal of good optical quality was grown by the flux method. The structure of YbAl3(BO3)4 crystal was determined by single-crystal X-ray diffraction. The experiment shows that YbAl3(BO3)4 belongs to the d...YbAl3(BO3)4 crystal of good optical quality was grown by the flux method. The structure of YbAl3(BO3)4 crystal was determined by single-crystal X-ray diffraction. The experiment shows that YbAl3(BO3)4 belongs to the double bo-rates with a trigonal structure. The space group is R32 and its unit cell constants were measured to be a = 0.92965 nm, c=0.72129 nm, V = 0.53673 nm3, Z=3. The transmittance spectra were measured. The cut-off of YbAl3(BO3)4 crystal is 216 nm, and there are two absorption peaks located at 940 and 975 nm from 190 nm to 2600 nm. The thermal properties of YbAl3(BO3)4 crystal were studied for the first time. The average thermal expansion coefficients were determined to be 2×10-6/℃, 9.5×10-6/℃along a- and c- direction. The specific heat of YbAl3(BO3)4 crystal was measured to be 0.6695 J·(g·℃) -1 at room temperature . All results indicate that the YbAl3(BO3)4 crystal is an excellent stoichioimet-ric laser material.展开更多
A novel tetranuclear nickel(II) complex [NiaL2(DMF)2(H20)2'2DMF] (1, H4L = azo-enolic-2-hydroxybenzamide, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by elemental analysis, UV, IR and...A novel tetranuclear nickel(II) complex [NiaL2(DMF)2(H20)2'2DMF] (1, H4L = azo-enolic-2-hydroxybenzamide, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by elemental analysis, UV, IR and X-ray single-crystal diffraction characterization. Complex 1 crystallizes in the monoclinic system, space group P21/n with a = 8.8944(11), b = 14.4583(18), c = 18.097(2) A, fl = 90.00(2), Z = 2 , V = 2327.2(5) A3, C40H48NI2Ni4OI4, Mr = 1155.66, Dc= 1.649 g/cm3,μ=1.672 mm1, F(000) = 1192, R = 0.0392 and wR = 0.0958. The local coordination environment around the nickel ions exist a distorted octahedral and quadrangle geometry in the molecular structure. Complex 1 exhibits strong photoluminescent emission in the ultraviolet region at room temperature. The electrochemical studies reveal that redox of Nia+/Ni2+ in the complex is a quasi-reversible process.展开更多
A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic ...A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.展开更多
γ-LiAlO2 single crystal is a promising substrate for GaN heteroepitaxy. In this paper, we present the growth of large-sized LiAlO2 crystal by modified Czochralski method. The crystal quality was characterized by high...γ-LiAlO2 single crystal is a promising substrate for GaN heteroepitaxy. In this paper, we present the growth of large-sized LiAlO2 crystal by modified Czochralski method. The crystal quality was characterized by high-resolution X-ray diffraction and chemical etching. The results show that the as-grown crystal has perfect quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec and etch pits density of (0.3- 2.2)×10^4 cm^-2 throughout the crystal boule. The bottom of the crystal boule shows the best quality. The optical transmission spectra from UV to IR exhibits that the crystal is transparent from 0.2 to 5.5μm and becomes completely absorbing around 6.7μm wavelength, The optical absorption edge in near UV region is about 191 nm.展开更多
The ligand of N-(2-hydroxybenzylideneamino)-1,8-naphthalimide (HL) and its metal complexes of CuL2 (1) and CoL2 (2) have been synthesized. Elemental analysis, IR and X-ray single-crystal diffraction characteri...The ligand of N-(2-hydroxybenzylideneamino)-1,8-naphthalimide (HL) and its metal complexes of CuL2 (1) and CoL2 (2) have been synthesized. Elemental analysis, IR and X-ray single-crystal diffraction characterizations for 1 and 2 have been carried out. In the complexes of 1 and 2, the central metallic ions of Cu^2+ and Co^2+ coordinate with two deprotonated ligands of L-, respectively and adopt distorted square planar geometries. The thermal analysis result shows that the two complexes undergo two similar decomposition processes because of their similar geometric configurations. For the two complexes, fluorescence spectra measurements indicate that complex CoL2 emits stronger blue fluorescence than HL and the complex CuL2 does not emit fluorescence at all.展开更多
文摘The europium p-chlorobenzoate complex with 1, 10-phenanthroline was synthesizd in the ethanol solution. The crystal structure of the complex, Eu (p-ClBA)3·phen (p-ClBA: p-chlorobenzoate, phen:1,10-phenanthroline), was determined by the X-ray diffraction. The complex crystalizes in triclinic,space group Pl with a=1. 0054 (2), b=1.1858(3), c=1.4349 (7) nm,α=110. 52(3), β=96. 52(3), γ= 101. 95(2)°, V=1. 5348(8) nm3, z=1, Dx=1. 729 g/cm3,Mr=1597. 72, T= 299±1 K. The coordination number of the europium ion is eight. The coordination geometry of the Eu3+ ion is a distorted square antiprism. In the 7F→5Do excitation spectrum of the complex, there is one sharp peak at 580. 04 nm. This shows that the complex has one Eu3+ site only. 5Do→7Fj(j=1 ̄4) luminescence spectra have been obtained by the selectively excited 5Do level of the complex, which indicates that Eu3+ ions in the complex have equally chemical environments. Raman spectrum shows more than one coordination modes for the carboxylate groups in the complex. This is in agreement with the results of the structure determination.
文摘The neodymium tungstate single crystals Nd-2(WO4)(3) were grown using the Czochralski method. The energy level scheme of Nd3+, was obtained through the spectral measurement. The upconversion luminescence of the crystals at 457 and 657 nm, corresponding to the (D5/2-->I11/2)-D-4-I-4 and (2)G(7/2)-->I-4(9/2) transitions, respectively, excited by 808 nm of a laser diode, was observed at room temperature. The fluorescence intensity and the excitation light power have a linear relationship at 457 nm and a quadratic relationship at 657 nm.
文摘The crystal structure of europium tri(dibenzoylmethanate) complex with 2.2'-bipyridyl,C70 H57 N2 O8 Eu, has been determined by X-ray diffraction. The complex crystallizes in the triclinic space group P1. The cell dimensions are a=1.3375(1) nm.b=1.8591(2) nm, c=1.1339(3) nm,α= 95.89(9) °,β=93.36(1)°,γ=85.48(1)° and Z=2. The total number of 5413 independent reflections with I>3σ(I) were used for the structure determination. The final calculated R value is 0.039. The central europium ion is octa-coordinated by six oxygen atoms and two nitrogen atoms forming a distorted square antipnsm (SAP) with the local symmetry C1. Using the Eu3+ ion as a luminescence probe. the high resolution excitation and emission spectra measured at 77 K indicate only one Eu3+ site existing in the complex. The emission spectra of 5D0→7Fj transition display the symmetry of the Eu3+ site is C1.
文摘The ionoluminescence (IL) spectra of a ZnO single crystal irradiated with 2.5?MeV H++ ions reveal that its intensity decreases with increasing the ion fluence, which indicates that the concentration of luminescence centers decreases with irradiation. The Gaussian decomposition results of the ZnO IL spectrum with a fluence of 1.77×10^11ions/cm^2 show that the spectrum is a superposition of energy levels centered at 1.75eV, 2.10eV, 3.12eV and 3.20eV. The four peaks are associated with electronic transitions from CB to VZnZn, CB to Oii, Znii to VB and the decay of self-trapped excitons, respectively. The results of single-exponential fitting demonstrate that different luminescent centers have different radiation resistance, which may explain why the emission decreases more slowly in the NBE band than in the DBE band. The agglomeration of larger point clusters accounts for the decrease in the concentration of luminescence centers and the increase in the concentration of non-luminescence centers, which indicates that the defect clusters induced by ion implantation act as nonradiative recombination centers and suppress light emission. The results of the photoluminescence spectra of a virgin ZnO single crystal and a ZnO single crystal irradiated with a fluence of 3.4××10^14ions/cm^2 show that compared with the virgin ZnO, the emission intensity of irradiated ZnO decreases by nearly two orders of magnitude, which demonstrates that the irradiation effect reduces radiative recombination and enhances nonradiative recombination. The conclusions of photoluminescence are consistent with the IL results.
基金supported by the National Natural Science Foundation of China(21401097)
文摘A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.
文摘Er^3+ :Y0.5Gd0.5VO4 crystal with good optical quality was grown by Czochraski method. The structure of the crystal was determined by X-ray powder diffraction method. The segregation coefficient of Er^3 + ions in the crystal was measured by the ICP method. The absorption and emission spectra were also measured. On the basis of the spectra, the absorption cross-sections, emission spectrum FWHM and fluorescence lifetime of the crystal were calculated. From the properties mentioned above.
基金Project supported by the Shanghai Leading Academic Disciplines,China(Grant No.S30107)
文摘The effect of laser energy density on the crystallization of hydrogenated intrinsic amorphous silicon (a-Si:H) thin films was studied both theoretically and experimentally. The thin films were irritated by a frequency-doubled (λ= 532 nm) Nd:YAG pulsed nanosecond laser. An effective density functional theory model was built to reveal the variation of bandgap energy influenced by thermal stress after laser irradiation. Experimental results establish correlation between the thermal stress and the shift of transverse optical peak in Raman spectroscopy and suggest that the relatively greater shift of the transverse optical (TO) peak can produce higher stress. The highest crystalline fraction (84.5%) is obtained in the optimized laser energy density (1000 mJ/cm2) with a considerable stress release. The absorption edge energy measured by the UV- visible spectra is in fairly good agreement with the bandgap energy in the density functional theory (DFT) simulation.
文摘The crystallographic properties and R aman spectra of the title compound ZnCd(SCN) 4, which is a new nonlinear optica l crystal(NLO), are reported for the first time. This crystal is orthorhombic and its space group is I - 4 with unit cell parameters a =1.113 5(0.2) nm, c =0.437 60(1) nm. There are two formulas per unit cell. Raman spectra of zinc cadmium thiocyanatec (ZCTC) are given and the electron activities in the crystal are shown.
文摘The structure of Tb∶Mo∶PbWO4 crystals was investigated by Raman spectra and the results showed that the spectra were varied differently by doping dopants in different ranges of shift. Rotation-vibration, curving-vibration and non-symmetrical stretching-vibration had been investigated on the spectra. Rotation-vibration intensity of [WO4]2-group is weakened and curving-vibration intensity is undergirded; low Mo6+ doping enhances the intensity of non-symmetrical stretching-vibration, with the concentration of Mo6+ increasing, the intensity is weakened. So it could be inferred that Tb3+ ion replaced the vacancy of Pb, when achieving at a certain concentration, Tb3+ ion would substitute for the lattice of Pb2+, Mo6+ ion would substitute for W lattice and generate [MoO4]2-new group, these are the main reason for the properties changing. Furthermore it could suggest that the impurity ions doped in tetrahedral positions, strongly affect the electron-phonon coupling in [WO4]2-, which makes the intensities of the vibration changed regularly.
文摘Sodium 3,5-bis(hydroxyimino)-1-methyl-2,4,6-trioxocyclohexanide C7H5N2NaO5 (I) has been isolated as the only product of the reaction of nitrosation of methylphloroglucinol. The structure of the titled compound has been determined from single crystal X-ray diffraction data. The hydrated C7H5N2NaO52.5H2O crystallizes in the monoclinic space group C2/c, with a(?) 16.408(3);b(?) 12.446(3);c(?) 13.716(3);(o) 126.34(3). The planar organic anion exists in a triketo-dihydroxyimino form with the C–O and C–N distances from 1.220(2) to 1.271(2)?? and from 1.292(2) to 1.293?? respectively. In the IR spectrum of I, the sharp absorption band occurred at 1681 cm-1 due to C=O stretching indicating the strong H-interactions. The correlations of theoretical (DFT-B3LYP/aug-cc-pVDZ) and experimental UV-vis absorption spectra in neutral and alkaline ethanolic solutions showed the existence of hydroxyimino-nitroso tautomerism while ionization of I.
文摘The crystal structure of spiro[2.2”]acenaphthene-1”-onespiro[3.3’]-5’-(2,3-dichlorophenylmethylidene)-1’-methylpipe-ridin-4’-one-4-(2,3-dichorophenyl) octahydroindolizine was elucidated by single crystal X ray diffraction. The title compound C37H30Cl4N2O2, crystallizes in the orthorhombic system, space group P212121 with a = 8.4610(4) , b = 16.0926(6) , c= 23.8997(11) and Z = 4. The central piperidine ring adopts twisted conformation, the piperidine of octahydroindolizine ring is in chair conformation and the pyrrole ring is in slightly twisted envelope conformation. Details of the synthesis, NMR, crystal structure determination and intra- and inter- molecular interactions of the compound are given.
文摘Reinvestigation of the growth of L-proline succinate (1) (Paramasivam and Ramachandra Raja, Journal of Crystallization Process and Technology, 2 (2012) 21 - 24;Balamurugaraj et al., Journal of Material Physics and Chemistry 1 (2013) 4 - 8) and L-threonine zinc acetate (2) (Puhal Raj and Ramachandra Raja, Photonics and Optoelectronics, 2 (2013) 56 - 64) is reported. Slow evaporation of an aqueous solution containing equimolar quantities of L-proline and succinic acid (for 1) and L-threonine and zinc acetate (for 2) results in the fractional crystallization of succinic acid (in the first case) and L-threonine (in the second case) and not any novel organic non-linear optical (NLO) crystals. In this paper, the usefulness of infrared spectra for correct product characterization is demonstrated.
文摘According to the Van Uitert experimental equation, crystal-lattice environment of Eu^(2+) in the Sr_4Si_3O_8Cl_4 crystal was discussed. By adding Mg^(2+) to the host lattice, Sr_(4- x )Mg_ x Si_3O_8Cl_4∶Eu^(2+) was synthesized and the emission peak shifted from blue-green (488 nm) to blue-violet (411 nm) with the increase of amount of the magnesium which replaced the strontium. By analyzing the spectra of Sr_(4- x )Mg_ x Si_3O_8Cl_4∶Eu^(2+) the two Eu^(2+) emission centers were found because of the change of crystal-lattice environment in the host and the crystal structure was obtained by X-ray diffraction data.
基金Financial supports received from the scientific research foundation of Sanming University(No.B201406/Q)Education Scientific Research Project of Fujian Province(No.JA15480)
文摘A new uranium(Ⅵ)-polycarboxylate framework with honeycomb(6,3) nets {[Zn(phen)_2(H_2O)_2][(UO_2)_2(BDC)_3]·2H_2O}n(1, BDC = benzene-1,4-dicarboxylate) was hydrotherrmally synthesized by the reactions of Zn(NO_3)_2·6H_2O with phenanthroine, UO_2(NO_3)_2·6H_2O and benzene-1,4-dicarboxylate. The complex was structurally characterized by FT-IR spectroscopy, powder XRD and X-ray single-crystal diffraction. Crystal data for 1: monoclinic, space group Cc with M_r = 1522.19, a = 14.9385(10), b = 20.4922(13), c = 15.9728(10) ?, β = 100.1240(10)°, V = 4813.5(5) ?~3, Z = 4, D_c = 2.100 g?cm^(–3), μ = 7.293 mm^(–1), F(000) = 2872, the final R = 0.0224 and w R= 0.0677 for 6522 observed reflections with I 〉 2σ(I). Hydrogen bonds and π-π stacking interactions contribute to the structural extension and stabilization. Experimental band gap of about 3.57 e V indicates its broad gap semiconductor nature. UV-Vis spectra and solid-state luminescence were discussed in detail. The compound exhibits photocatalytic activities for the degradation of rhodamine B.
基金Project supported by the National Natural Science Foundation of China (50323006 and 50590401/E01)
文摘YbAl3(BO3)4 crystal of good optical quality was grown by the flux method. The structure of YbAl3(BO3)4 crystal was determined by single-crystal X-ray diffraction. The experiment shows that YbAl3(BO3)4 belongs to the double bo-rates with a trigonal structure. The space group is R32 and its unit cell constants were measured to be a = 0.92965 nm, c=0.72129 nm, V = 0.53673 nm3, Z=3. The transmittance spectra were measured. The cut-off of YbAl3(BO3)4 crystal is 216 nm, and there are two absorption peaks located at 940 and 975 nm from 190 nm to 2600 nm. The thermal properties of YbAl3(BO3)4 crystal were studied for the first time. The average thermal expansion coefficients were determined to be 2×10-6/℃, 9.5×10-6/℃along a- and c- direction. The specific heat of YbAl3(BO3)4 crystal was measured to be 0.6695 J·(g·℃) -1 at room temperature . All results indicate that the YbAl3(BO3)4 crystal is an excellent stoichioimet-ric laser material.
基金Supported by the Key Laboratory of Environmental Engineering,Protection and Assessment of Guangxithe National Water Pollution Control and Management of China(No.2008ZX07317-02)the Startup Foundation for Dr.of Guilin University of Technology
文摘A novel tetranuclear nickel(II) complex [NiaL2(DMF)2(H20)2'2DMF] (1, H4L = azo-enolic-2-hydroxybenzamide, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by elemental analysis, UV, IR and X-ray single-crystal diffraction characterization. Complex 1 crystallizes in the monoclinic system, space group P21/n with a = 8.8944(11), b = 14.4583(18), c = 18.097(2) A, fl = 90.00(2), Z = 2 , V = 2327.2(5) A3, C40H48NI2Ni4OI4, Mr = 1155.66, Dc= 1.649 g/cm3,μ=1.672 mm1, F(000) = 1192, R = 0.0392 and wR = 0.0958. The local coordination environment around the nickel ions exist a distorted octahedral and quadrangle geometry in the molecular structure. Complex 1 exhibits strong photoluminescent emission in the ultraviolet region at room temperature. The electrochemical studies reveal that redox of Nia+/Ni2+ in the complex is a quasi-reversible process.
基金Supported by the Scientific Research Foundation of Higher Education Institutions of Ningxia(No.NGY2017004)the National Natural Science Foundation of China(Nos.21763022 and 50564043)the Major Innovation Projects for Building First-class Universities in China’s Western Region(No.ZKZD2017003)
文摘A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.
基金supported by the Project of High Technology Research and Development of China(2006AA03A101 and 2006AA03A103)the National Natural Science Foundation of China(60676004)the Science Research Program of Shanghai(05PJ14100 and 06dz11402).
文摘γ-LiAlO2 single crystal is a promising substrate for GaN heteroepitaxy. In this paper, we present the growth of large-sized LiAlO2 crystal by modified Czochralski method. The crystal quality was characterized by high-resolution X-ray diffraction and chemical etching. The results show that the as-grown crystal has perfect quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec and etch pits density of (0.3- 2.2)×10^4 cm^-2 throughout the crystal boule. The bottom of the crystal boule shows the best quality. The optical transmission spectra from UV to IR exhibits that the crystal is transparent from 0.2 to 5.5μm and becomes completely absorbing around 6.7μm wavelength, The optical absorption edge in near UV region is about 191 nm.
基金supported by the Fund of Jiangsu Key Laboratory for Chemistry of Low-dimensional Materials (JSKC08047)Fund of Huanyin Teachers College (08HSJSK003)
文摘The ligand of N-(2-hydroxybenzylideneamino)-1,8-naphthalimide (HL) and its metal complexes of CuL2 (1) and CoL2 (2) have been synthesized. Elemental analysis, IR and X-ray single-crystal diffraction characterizations for 1 and 2 have been carried out. In the complexes of 1 and 2, the central metallic ions of Cu^2+ and Co^2+ coordinate with two deprotonated ligands of L-, respectively and adopt distorted square planar geometries. The thermal analysis result shows that the two complexes undergo two similar decomposition processes because of their similar geometric configurations. For the two complexes, fluorescence spectra measurements indicate that complex CoL2 emits stronger blue fluorescence than HL and the complex CuL2 does not emit fluorescence at all.